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CHAPTER 1 - DESCRIPTION
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87-900-045-01
(D)
1.2.2 Basic unit
HeliTest is driven by a single chip microcomputer and
consists of:
•
front panel display and keyboard;
•
microprocessor PCB, where sensor temperature
controller and pressure detector circuitries are
located;
•
high voltage PCB, which contains the high voltage
power supply for pressure detector;
•
Helium sensor (based on a silica capillary), with
pressure detector;
•
sampling line, where a membrane pump conveys
the sampling gas into the detector;
•
sniffing probe, connected to the module by a
standard 1.5 meter long flexible extention.
A dedicated non-volatile RAM is used to store the
operating parameters and information if power failure
occurs for a period of 10 years accumulated off time.
Figure 1-3 - Basic unit